Improved apparatus for severing wrappers from webs and feeding said wrappers to package-making machines

摘要

368,836. Cutting and perforating machines. ROSE, A. G. and ROSE BROS. (GAINSBOROUGH), Ltd., Albion Works, Gainsborough, Lincolnshire. Dec. 12, 1930 No. 37479. [Classes 31 (i) and 31 (ii).] Relates to web-feed apparatus of the type in which the web is provided at spaced intervals along its length with designs or the like and control areas preferably in the form of translucent or opaque spots, one in definite relation to each design, the web being fed past a lamp, which directs a beam of light to it and thence to a light-sensitive device, the change in current in the device consequent upon the passage of the control area through the beam of light being utilized to co-ordinate some other operation such as cutting or perforating, and consists in the provision of an electromagnetically-operated clamp controlled by the light-sensitive device upon the appearance of a control area in the beam of light to interrupt the forward travel of the web and clamp it during the subsequent operation. The web 10 is fed by a continuously rotating roll 12 and its co-operating roll 13, until a control area comes over an aperture in the feed table beneath which are located a lamp 19 and a selenium cell 20, connected through a relay 26, battery 25, and contact members 33, 34 with an electromagnet 24. The contact 33 wipes over a conducting ring 31, the periphery of which is broken by an insulating segment 32, attached to the roll 12 ; the contact 34 also bears upon the ring 31 but upon a reduced diameter thereof so that it never contacts with the segment 32. Owing to the presence of an opaque area, the amount of light reflected by the web from the lamp 19 to the cell 20 is varied, the current variation produced being employed to attract an armature 22 of the electromagnet 24 and thus rock a bell-crank lever 21 to lower the clamp 23 against the upper surface of the feed table and arrest the motion of the web. The cutter 18 then operates. The roll 12 continues to feed the web 10, which accumulates behind the clamp 23, until a recessed portion 28 of the roller 12 comes over the co-operating roller 13 when the web ceases to be fed forward. The insulating strip 32 has meanwhile engaged the contact 33 to break the circuit of the electromagnet 24, the armature of which is accordingly retracted by spring means to raise the clamp 23, at the moment when an arcuate portion 35 on a second continuously rotating roller 15 comes into operative engagement with its co-operating roller 16. The roller 15 draws the web forward until it is rendered inoperative by the relieved portion 29 of its periphery coming over the web, at which time the first roll 12 again becomes operative.